表面磁极化子的光学声子平均数

采用Tokuda改进的线性组合算符、Lagrange乘子和变分法,讨论了强、弱耦合表面磁极化子的性质。计算了极化子的基态能量和光学声子平均数。以AgCl和ZnS晶体为例进行了数值计算。讨论了表面磁极化子振 动频率、基态能量和光学声子平均数与磁场B和拉格朗日乘子u的关系。

Mean Number of Optical Phonon of Surface Magnetopolaron

In recent years, the properties of magnetopolaron in polar crystals have been of considerable, interest.Larsen proposed a fourth-order perturbation method to calculate the ground state energy of two-dimensional polaron in a magnetic field.Kandemir et aL.discussed the ground-state and first-excited-state energy of two-dimensional large magnetopolaron by using recently introduced squeezed Landau states.Wei et al.studied the cyclotron resonance mass and resonance frequency of the interface magnetopolaron using the Green’s function method.Xiu et al.using the variational method, studied the property of strong coupling magnetopolaron in a polar crystal slab.The energies of the ground state and the excited state were presented and the electron-surface optical (SO) phonon interactions at ground state and excited state were studied emphatically.Using Huybretch’s variational method and unitary transformation, the strong coupling between electron and surface optical (SO) phonons and the weak coupling between electron and bulk longitudinal optical (LO) phonons were studied systematically by Xia et al..Wang et al.investigated the magnetic field and temperature dependence of the properties of a magnetopolaron at the interface of polar-polar crystals in an external magnetic field by using the generalized Haga perturbation method.The properties of surface polaron in a magnetic field have been further discussed by the present authors and co-workers.Tokuda studied the property of the mean number of the optical and the piezoelectric polarons and the mean number of the acoustic and optical polarons via deformation potential by using improved variational method.However, the mean number of optical phonon of surface magnetopolarons has not been studied so far.In this paper, the properties of surface magnetopolaron which is a strong-and weak-coupling of optical phonon was discussed by using Tokuda’s improved linear combination operator and the Lagrange multiplier and the variational method.The ground state energy and the mean number of optical phonons of the strong-and weak-coupling magnetopolaron were calculated.Numerical calculations for AgCl and ZnS crystals, as an example, were performed.The relational of the vibration frequency, the ground energy and the mean number of optical phonon to magnetic field B and Lagrange multiplier u were discussed.The result illustrates that the vibration frequency λ of surface magnetopolaron will increase with increasing magnetic field B and Lagrange multiplier u, the ground state energy E will increase with increasing u and decreasing B, the mean number of optical phonon N will increase with increasing u.